Power supply system



Jan. 28, 1941. M E

rowrm SUPPLY SYSTEM Filed Feb. 12, 1940 2 Sheets-Sheet 1 Jan. 28, 1941.K. EMDE POWER SUPPLY SYSTEM Filed Feb. 12, 1940 2 Sheets-Sheet 2INVENTOR. Jill/'25 .ErndQ v IV I, @ia

I I I I I r I UNITED STATES PATENT. OFFICE POWER SUPPLY SYSTEM,

Kurt Emde, Chicago, 111., assignor to Zenith Radio Corpogation, Chicago,111., a corporation of Illino Application February 12, 1640, Serial No.318,422

Claims. (01. 171-97) This invention relates tola power supply syscircuitcontrolling switch, but without the plug; tem for a device operable byelectric currents difand fering in character and/or voltage, and morepar- Figure 5 is an inverted bottom plan view of the ticularly concernsa novel circuit controlling arswitch and plug of Fig. 3, taken upon theline 5 rangement through which such a device may be and viewed in thedirection'of the arrows 55 of 5 selectively connected with one oranother of a Fi 4. plurality of sources of electric current supply. Asis well known to those familiar with the The principal object of theinvention is to pro-- radio art, certain types of radio receiving setsare vide an arrangement 01' the aforesaid character designed foroperation by electric current sup- 1 which is operable in a novel mannerto not only plied either by power service lines or by battery. effectconnection of the device with a selected The type of current supplied bythe power service one or another of a plurality of sources of eleclinesmay be either A. C. or D. C., and the voltage tric current supply, butto prevent connection of may be much higher than that of the battery,the device with more than one of such sources and the battery currentsupply may be either at a time, and to eflect the connection of the fromstorage or secondary batteries or from dry- 15 proper power supplycircuit of the device with cell or primary batteries. Regardless of thetype the selected source of electric current supply. or voltage of thecurrent available from the pow- Another object of the invention is tohave the er service lines, and whether storage or dry-cell novel mannerof operating the arrangement so batteries be employed, it is'importantthat, in

simple and so conveniently and obviously presentsuch sets, the batterycircuits be disconnected a. ed for use that understanding and cautionupon when the power line circuits are connected, and the part of theuser is not required, to the end it is customary to equip the sets witha manuthat the power supply circuits oi. the device may ally operablebattery switch for this purpose, but not be connected with the wrongsource of curthere is no provision against misadjustment of rent and maynot be connected with more than the switch. Where a single-throw battery25 one of said sources at a time. Further explanaswitch is provided andis inadvertently left closed tion of these objects and other objects ofthe inwhen the power line circuit is connected, the revention willappear in the description to follow. sult will be the draining of thebattery, and if a While the invention is primarily designed fordouble-throw change-over switch is provided for use in connection withthe power supply circuits alternately connecting the battery circuit orthe 30 of radio receiving apparatus and will be so depower line circuitand it is left in the wrong posiscribed, it will be evident that itsusefulness is tion, the battery circuit is unintentionally emnotconfined to such apparatus, and I desire not ployed and the batteryexhausted, while the user, to be limited thereto, having plugged intothe power service line out- In the drawings-- I let-socket, believespower service line current is 35 Figure 1 is a perspective view,illustrating being supplied. It will be evident from the folthe back ofa portable radio receiving set, with lowing description that the presentinvention the demountable rear panel of the outer casing providesagainst misadjustment of the switch.

removed to disclose the arrangement of the prin- For convenience inillustrating the embodiment 4o cipal elements of the constructionhereinafter deoi. my invention in radio receiving pp tus, I scribed asembodying my invention; have shown in Figure 1 of the accompanyingFigure 2 is a circuit diagram showing an ardrawings the back of aportable radio receiver rangement, selected for illustrative purposesonly, I, the rear outer panel 2 of which has been de- 01 the powersupply circuits of radio receiving mounted from the casing and set asideto disapparatus, with which are associated the circuit close the innerpanel 3, the storage brackets 4-4 4| controlling switch and powerservice line plug secured thereto, the power service line cord 4employed in the herein described embodiment of wound upon said storagebrackets, the plug 6 atmy invention; tached to the free end of saidcord, the battery Figure 3 is a fragmentary vertical sectional leads I,and the plug receptacle 8. The dry-cell 60 view, upon an enlargedscale,,taken upon the line or primary battery 9 is located at the bottomof 3-3 of Fig. l, transversely through the circuit the receiver, forwardof inner panel 3, as indicontrolling switch, showing the power serviceline cated by dotted lines. If the receiver is to be plug inswitch-operating position; operated by electric current supplied bypower Figure 4 is a vertical sectional view, taken upon service lines,the cord 5 may be unwound from 68 the line 4-4 of Fig. 3, longitudinallythrough the the storage brackets 44 and the plug 6 plugged so back ofthe casing, with the cord extending through a notch (not shown) in theouter panel 2 similar to the notch I I shown in the edge-part,

of inner panel 3. Simple means for holding the panel 2 in position topermit convenient removal and replacement thereof is provided, such asby stepp n a pair of dowel-pins, one of which is shown at l2, into thesockets |3|3 and press ing the catch-member 4 between the spring tonguesof the retaining clip l5. Obviously, when the receiver is to be carriedabout, the plug 6 will be removed from the wall-socket l0, and the cord5 and plug 6 may be stowed within the space between the outer and innerpanels, 2 and 3, respectively. If the receiver is to be operated byelectric current supplied by the battery 9, the prongs |6-| 6 of theplug 6 are pushed into the prong-receiving apertures l1-|1 of the plugreoeptacle 8, as indicated in dotted lines in Figure 1 and as shown inFigures 3 and 5. When used in this way, the plug 6 serves as a key formechanically operating the change-over switch in a manner to bedescribed, but the prongs make no electrical contact and the cord 5 doesnot connect the receiver with any electric current supply.

Inner panel 3 is removably secured in position within the casing in anydesired manner and is apertured at l6 to provide access to the plugreceptacle 8 and a passage for the battery leads 1, which are broughtout therethrough to the rear of the panel and connected with the battery9 through an aperture H! by means of the fourpronged terminal plug 20.Battery 9 may be removed and replaced by disconnecting the terminal plug26 therefrom and removing the inner panel 3.

Referring, now, to Figures 3, 4 and 5 of the drawings, I have showntherein a change-over switch at 2|, the particular interior constructionof which will be described, but is not a part of this invention. It isto be understood that any switch construction may be employed which issuitable for the purpose and method of operation hereinafter set forth.Plug receptacle 8 is preferably struck out and formed of stiff sheetmetal and, when positioned with the switch thereabove as herein shown,comprises a horizontally extending table-portion 22 .and two downwardlyturned vertical flange-portions 23 and 24. Flange-portion 23 is firmlysecured preferably to the rear vertical wall of the metal chassis 25, asby screws 26-26, and flange-portion 24 is provided with theprong-receiving apertures |1-|1. Switch 2| is firmly secured upontable-portion 22, as by screws 21-21. Tableportion 22 is bisected by aslot 28, one end-part of which extends a short distance down into theflange-portion 24 and forms the upper one of the two prong-receivingapertures |1-|1 therein. As shown in Figure 5, when the prongs |6-|6 ofplug 6 are pushed into the prong-receiving apertures |1-|1, the upperone of said prongs occupies the slot 28, one side of which is cut awayto form a recess 29. A tongue is bent from flange-portion 23 to extendhorizontally therefrom toward flange-portion 24 just below the lower oneof the prong-receiving apertures |'|-|1 and serves as a guide-supportbeneath the lower. one of the prongs |-6-|6, the upper one of saidprongs being similarly guided by the lower surface of the switch-unit2|, the arrangement being such that, when the prongs |6-|6 are pushedinto the respective prong-receiving apertures I'd-I1, they will travelalong and be guided between the tongue 30 and the bottom of theswitch-unit 2 I.

Switch-unit 2| comprises a fixed contact-supporting plate 3| and amovable member 32, both being formed of insulating material, such asfibre or vulcanite, and encased within a two-part metal shield having abase-member 33 and a cap 34. Base-member 33 has a flat bottom-portionand two upwardly turned side flanges 3636. The opposite end-parts ofbottom-portion 35 are provided with threaded openings for the attachingscrews 21-21, and the upper edges of side flanges 3636 are formed withtongue-clips 31-31. Movable member 32 slides upon the bottom-portion 35between side flanges 3636 and is formed with a downwardly projecting lug38 which extends through an opening 39 in bottomportion 35 and throughthe slot 28 and recess 29 in the table-portion 22 of plug-receptacle 8.An end wall plate 40 is secured to the side flanges 3636 to close oneend of the trough formed thereby, and a coiled compression spring 4| ispositioned between the plate 40 and the adjacent end of the movablemember 32, the action of the spring being such that, when the prongs|6-|6 of plug 6 are removed from the respective prong-receivingapertures |1-|-1, it will hold the movable member 32 in the positionillustrated in Figure 4, wherein the lug 36 engages the right-hand endof the opening 39 and is partly across slot 28 and partly within recess29. As viewed in Figures 3 and 5, the right-hand and rear verticalsurfaces of the lug 38 are beveled or backed away, as at 42, so that,when the upper one of the prongs |6-|6 is pushed into the slot 29, therounded end thereof will engage with the beveled surface 42 of the lugand force it to one side out of the slot 28' and fully into the recessofthe plate and are bent inwardly over the top thereof, as shown at 43.Two sets of three contacts each, 44 to 46 and 41 to 49, respectively,are arranged in line in plate 3|, the contacts being formed and securedin position in the manner illustrated in Figure 3, each contact havingan upwardly extending arm 50 to which one of the circuit leads, to belater described in connection with Figure 2, is soldered or otherwiseconnected. The contact arms 50 and the ends of the leads connectedthereto are enclosed by the metal shield cap 34, which is lined withinsulating material 5| and provided at the top with an opening 52 forthe passage of the leads therethrough. Cap 34 removably fits down overand :grrounds the upstanding parts of base-member Directly below theline of contacts 44 to 49, the upper face of movable member 32 ischanneled longitudinally, leaving the upstanding side flanges 53-53 forguiding engagement with the under face of plate SI, and a pair ofcylindricalr pockets l4 54 are formed in the body of the member, openingupwardly into the bottom of the channel. Each of said pockets 5H4 housesa 5 coiled compression spring II which surrounds the central stem andacts upwardly beneath the flat circular head of one of two bridgingcontacts "41. The diameter of the flat circular head of each of the twocontacts "-51 is suiiicient to bridge two of the contacts 44 to 48,against which it is held by the action of its spring 5!. As shown inFigure 4, when the movable member 32 is in its rightward position;contact I will bridge contacts 45 and 46 and contact I! will bridgecontacts is and 49, while, as indicated by dotted lines in Figure 2,when the member 32 is in its leftward position, contact 5' will bridgecontacts 44 and 45 and contact 51 will bridge contacts 41 and 48. It isto be understood that the successful employment of my invention is notin any sense dependent upon the particular arrangement shown in Figure2. The circuits therein diagrammed are intended to illustrate apracticable manner of connecting the several battery leads I and thepower service line leads 58-49 of the cord 5 with the change-over switch2|, and the employment of the switch to effect the proper adjustment ofthe power supply circuits of the device in accordance with the characterand/or voltage of the electric current supplied through connection ofthe device with the battery or with power service lines. I have alreadymentioned that a single-throw battery switch may be employed, ifdesired, and the circuit connections therewith would differ somewhatfrom those of Figure 2, but I prefer the double-throw change-over switchherein shown and described to insure the disconnection of the powerservice line supply when the battery is connected, thereby avoiding thepossibility of employing a separate plug to operate the switch andeffect the connection of the battery while the power service line isconnected and thereby frustrate one of the principal objects of myinvention, namely, to prevent connection of the device with more thanone source of electric current supply at the same time.

Since this invention is not necessarily concerned with the circuits ofthe radio receiving set, they have not been illustrated, but it may beexplained that the B-plus lead 80 extends to the plate circuit of thefirst audio frequency tube, B-plus lead 6| extends to the plate circuitsof the other tubes, and A-plus lead 62 is connected with the filament orcathode-heating circuit, and,

as is customary, these circuits are finally completed through a commonground return.

Still referring to Figure 2, wherein movable member 32 of switch 2| isindicated in full lines 3 in its rightward position, it may be seenthat, upon inserting plug 8 in a power service line socket, as indicatedat ill in Figure 1, and closing the on-off switch 4, power service linecurrent will be supplied to the device as follows: 5 lead 58 torectifier 65, thence through lead 88 to A-plus lead 62 and ground, andthrough lead 61, contacts 49, 51 and 48, and lead 88 to B-plus lead iiand ground, also through branch-lead 69 and switch 64 to B-plus lead andground, the sev- 70 eral circuits being completed through ground 63,switch 64, lead III, contacts 45, ii and II, and lead II to lead 59.When movable member 32 is in its leftward position, as indicated bydotted lines, the power service line will be disconnected, sincecontacts 46 and 49 will not be engaged by the respective bridgingcontacts 58 and 51, and battery current will be supplied to the deviceas follows: A-plus lead 12 directly to A-pluslead O2 and ground and backthrough ground 83, switch 64, lead 10, contacts 45, 56 and 44, to A- 5minus lead 13; also 'B-plus lead 14, through contacts 41, 51 and 48, andlead 68, to B-plus lead ii and ground, and through branch-lead 89 andswitch 84 to B-plus lead 60 and ground, returning through ground 63 andB-minus lead I5. 10

I claim:

1. A power supply system for radio receiving apparatus operable byelectric current of one character when connected with one source ofcurrent supply and operable by electric current of a 15 differentcharacter when connected with a different source of current supply, saidsystem comprising a circuit connecting plug having a contact prong forconnecting said apparatus electrically with said one source of currentsupply, a 20 mechanically operable switch controlling the connection ofsaid apparatus with said different source of current supply, and a plugreceptacle having a prong-receiving aperture to receive the contactprong of said plug, said aperture being so arranged with respect to saidswitch as to permit the insertion of the contact prong of said plug intosaid aperture to mechanically operate said switch and thereby effect theconnection of said apparatus with said different source of currentsupply.

2. A power supply system for radio receiving apparatus operable byelectric current of one character when connected with one source ofcurrent supply and operable by electric current of a different characterwhen connected with a different source of current supply, said systemcomprising a circuit connecting plug having a pair of contact prongs forconnecting said apparatus electrically with said one source of currentsupply, a circuit switch having a movable member controlling theconnection of said apparatus with said different source of currentsupply, and a plug receptacle having a pair of prong receiving aperturesto receive the contact prongs of said plug, one of said apertures beingso arranged with respect to said switch as to permit the insertiontherein of the respective one of the prongs of said plug to engage withand operate the movable member of said switch and thereby effect theconnection of said apparatus with said different source of currentsupply.

3. A power supply system for radio receiving apparatus operable byelectric current of one 55 character when connected with a first sourceof current supply and operable by electric current of a differentcharacter when connected with a second source of current supply, saidsystem comprising first and second circuit connections for 60 connectingthe apparatus with said first and second sources of current supply,respectively, a circuit connecting plug in said first circuit connectionhaving a contact prong for connecting said apparatus electrically withsaid first source 65 of current supply, a mechanically operablechange-over switch acting upon adjustment thereof to open either one andclose the other of said circuit connections, and a plug receptaclehaving a prong receiving aperture to receive the 70 contact prong ofsaid plug, said aperture being so located with respect to said switch asto permit the insertion and withdrawal of the prong of said plug intoand from said aperture to control the adjustment of said switch andthereby determine 7 which of said circuit connections shall be opened orclosed.

4. A power supply system for radio receiving apparatus operable byelectric current 01' one character when connected with a first source orcurrent supply and operable by electric current of a diiferent characterwhen connected with a second source of current supply. said systemcomprising first and second circuit connections for connecting theapparatus with said first and sec- .ond sources of current supply,respectively, a circated with respect to said switch as to permit theinsertion of the prong or said plug into said aperture to eflfect theadjustment of said switch to open said first and close the second ofsaid circuit connections. I

5. A power supply system for radio receiving apparatus operable byelectric current of one character when connected with a first source ofcurrent supply and operable by electric current or a difierent characterwhen connected with a second source oi. current supply, said systemcomprising first and second circuit connections for 5 connecting theapparatus with said first and second sources 01 current supply,respectively, a circuit connecting plug in said first circuit connectionhaving a contact prong for connecting said apparatus electrically withsaid first source 01' 10 current supply, a circuit change-over switchhaving'a movable member operablein one direction to close the first andopen the second of said circuit connections and operable in the otherdirection to cpen the first and close the second of 15 said circuitconnections, means acting upon said movable member to operate it in saidone direction, and a plug receptable having a prong receiving apertureto receive the contact prong of said plug, said aperture being solocated with re 2t spect'to said switch as to permit the insertion ofthe prongof said plug into said aperture to act upon said movable memberto operate it in said other direction against the influence of saidmeans. 25

KURT EMDE.

